Turn on clang format as an upload step for all the repo.

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 686ae511773be4835973f9e2dac4ab7d9776bd2b..34fb5e6c23e56842094019b4c549c96e61d23cc7 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -2315,6 +2315,8 @@ def CheckChangeOnUpload(input_api, output_api):
   results.extend(_CommonChecks(input_api, output_api))
   results.extend(_CheckValidHostsInDEPS(input_api, output_api))
   results.extend(
+      input_api.canned_checks.CheckPatchFormatted(input_api, output_api))
+  results.extend(
       input_api.canned_checks.CheckGNFormatted(input_api, output_api))
   results.extend(_CheckUmaHistogramChanges(input_api, output_api))
   results.extend(_AndroidSpecificOnUploadChecks(input_api, output_api))
@@ -2369,6 +2371,8 @@ def CheckChangeOnCommit(input_api, output_api):
       output_api,
       json_url='http://chromium-status.appspot.com/current?format=json'))
 
+  results.extend(
+      input_api.canned_checks.CheckPatchFormatted(input_api, output_api))

[Dan Beam, 2017/02/10 19:10:06]

fyi: this certainly appears to be running formatting checks on commit as well

[Dan Beam, 2017/02/10 20:11:39]

follow up: as dcheng@ mentioned on chromium-dev@: because this check returns
PresubmitPromptWarnings (rather than PresubmitErrors), this will not block a CQ

   results.extend(input_api.canned_checks.CheckChangeHasBugField(
       input_api, output_api))
   results.extend(input_api.canned_checks.CheckChangeHasDescription(